Single Flare > 12 gauge ~ 2.0mm > 6 gauge ~ 4mm > 4 gauge ~ 5mm > 2 gauge ~ 6mm > 1 gauge ~ 7mm > 5/8 inch ~ 16mm > 1-3/8 inch ~ 35mm > 1-1/2 inch ~ 38mm > 1-7/8 inch ~ 48mm